Assessing the value of information: a comparative analysis of meteorological observation setups in an irrigated German apple orchard

Due to climate change, managing irrigation systems requires adapting existing scheduling strategies based on monitoring meteorological, biophysical, and soil physical variables. For monitoring, there are many combinations of sensors, starting from low-cost IoT-based systems and ranging to scientific high-precision devices that offer a specific quality of measurements at a particular price. By explicitly modeling the value gained by more precise monitoring, the value of information (VOI) theory can determine whether additional information provided by site-specific monitoring setups is worth employing to manage the considered irrigation systems. Different levels of information about meteorological conditions are provided by (i) on-site systems (energy balance station, low-cost climate station, and a spatial grid of low-cost LoRaWAN temperature and humidity sensor), (ii) available public weather data, e.g., from a close climate station of the German weather service (DWD), and (iii) latest reanalysis data from the ERA5-Land product. To estimate the additional VOI of the different site-specific monitoring setups related to the reference defined by the DWD data, evapotranspiration, biomass, and yield data simulated by the Aquacrop model are compared. In addition, adapted scheduling strategies are derived using the Deficit Irrigation Toolbox (DIT).   This contribution presents the application of VOI theory for decision-making in the monitoring design of an irrigated apple farm in Werder (Germany) in 2023 and 2024.